Composition and stability of some bivalent transition metal complexes of 3,5-dinitrosalicylic acid

1970 ◽  
Vol 48 (6) ◽  
pp. 1007-1010 ◽  
Author(s):  
S. S. Dube ◽  
S. S. Dhindsa

The interaction of Zn2+, Mn2+, Hg2+, and Cd2+ ions with 3,5-dinitrosalicylic acid was investigated by potentiometric titrations in aqueous 0.1 M KNO3 medium. In all cases the formation of 1:1 complex was indicated. The stability constants in the pH ranges 4.5–8.0, 4.5–8.0, 5.0–8.0, and 5.5–8.0 were determined by applying the Calvin and Melchior's extension of Bjerrum's method and the log K values were found to be 3.70, 2.95, 3.20, and 2.85, respectively. A comparative study of the complexes of 3,5-dinitrosalicylic acid with other bivalent metal ions has also been incorporated. The stability constants of the transition metal complexes obey the order Cu > Ni > Co > Zn > Mn, in agreement with Irving and William's rule.

2015 ◽  
Vol 17 (2) ◽  
pp. 805-811 ◽  
Author(s):  
Pradeep R. Varadwaj ◽  
Arpita Varadwaj ◽  
Bih-Yaw Jin

Ligand(s)-to-metal charge transfer obtained from QTAIM charges unravel the Irving–William series for the equilibrium constants of late first-row bivalent metal ions.


1990 ◽  
Vol 68 (5) ◽  
pp. 774-781 ◽  
Author(s):  
Mohamed S. Abdel-Moez ◽  
Shaker L. Stefan ◽  
Mostafa M. El-Behairy ◽  
Mohamed M. Mashely ◽  
Basheir A. El-Shetary

The stepwise stability constants of VO(II), Mn(II), Cu(II), Ni (II), Co(II), Zn(II), Fe(III), and UO2(II) metal ions with 2-(2-acetylphenylhydrazone)-5,5-dimethyl-1,3-cyclohexane dione (2-APHDm), 3-(2-acetylphenylhydrazone)pentane-2,4-dione (2-APHA), 2-(2-acetylphenylhydrazone)-1-phenyl-1,3-butane dione (2-APHB), 2-(2-acetylphenylhydrazone)-1,3-diphenyl-1,3-propane dione (2-APHDB), and 3-(2-acetylphenylhydrazone)-1,1,1-trifluoropentane-2,4-dione (2-APHTA) were determined at 30 °C by pH titrations in 75% (v/v) dioxane–water solvent. In addition, metal complexes of three related β-diketones, 2-APHA, 2-APHB, and 2-APHDB have been synthesized and characterized by elemental analysis, uv–visible, ir spectra, and conductance in DMF and magnetic susceptibility measurements. The structure of the complexes have been proposed. Keywords: transition metal complexes of hydrazone-β-diketone ligands.


1962 ◽  
Vol 15 (4) ◽  
pp. 786 ◽  
Author(s):  
RW Green ◽  
GKS Ooi

Spectrophotometric and pH-titration methods have been used to determine the stability constants at 25 �C of complexes between transition metal ions and the anion of 6-hydroxymethylpyridine-2-carboxylic acid. This anion is found to be a weaker base and a weaker complexing agent than the pyridine-2-carboxylate ion. There is some evidence for steric hindrance of tris complexes.


2018 ◽  
Vol 69 (7) ◽  
pp. 1678-1681
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.


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